Piloted by a brave sort who never runs from a fight, but lacks ability. Even though his AC is well armored it's doubtful this alone will help him advance in rank.
Horizon is a middleweight two-legged AC equipped with the starter rifle, an energy shield, a back radar, a small rocket launcher and an overboost core.
Phaethon is not dangerous because he is poorly equipped, but he will be jumping (not flying) around shooting his Rifle and Small Rocket at you. His Rifle and rocket are not a threat, so avoid his attacks and attack him with your weapons.